In order to provide a more trouble free light waveguide connection proceeding between two points in a telecommunication system, a double light waveguide connection, i.e. a light waveguide connection having two separate fibers is provided. Given an interruption in the signal transmission over one fiber, a switch is undertaken to the other fiber that is then used for further signal transmission in place of the previously used fiber. The required switchover time during which the signal transmission is interrupted should thereby be optimally short.
One prior art solution for such a switchover (alternate circuit) between the two fibers of a double light waveguide connection proceeding between two nodes (also see ITU-T Study Group 13, Question 23/13, Contribution 15, 1993) is as follows. The optical signal is split onto two fibers (working fiber and redundant fiber) at the node of the transmission side, these two fibers being combined at the node of the receive side by an optical switch means via which the working fiber is connected to the node of the receive side during normal operation. Given a break in the working fiber, the switch means switches automatically due to the outage of the transmitted light, so that the redundant fiber is now connected to the node of the receive side instead of the working fiber. As a result of performing the switchover at the receive side, the interrupt time can be kept short. In such a solution, however, the working fiber continues to carry the optical signal up to the break point, this potentially endangering the maintenance or, respectively, repair personnel or a random observer as well due to the great bundling of the laser light carried therein.